MAN page from Other curl-7.19.0-1.i386.rpm

curl

Section: Curl Manual (1)
Updated: 10 July 2008
Index

NAME

curl - transfer a URL

SYNOPSIS

curl [options][URL...]

DESCRIPTION

curlis a tool to transfer data from or to a server, using one of the supportedprotocols (HTTP, HTTPS, FTP, FTPS, SCP, SFTP, TFTP, DICT, TELNET, LDAP orFILE). The command is designed to work without user interaction.

curl offers a busload of useful tricks like proxy support, userauthentication, ftp upload, HTTP post, SSL connections, cookies, file transferresume and more. As you will see below, the number of features will make yourhead spin!

curl is powered by libcurl for all transfer-related features. Seelibcurl(3)for details.

URL

The URL syntax is protocol dependent. You'll find a detailed description inRFC 3986.

You can specify multiple URLs or parts of URLs by writing part sets withinbraces as in:

http://site.{one,two,three}.com

or you can get sequences of alphanumeric series by using [] as in:

ftp://ftp.numericals.com/file[1-100].txt
ftp://ftp.numericals.com/file[001-100].txt (with leading zeros)
ftp://ftp.letters.com/file[a-z].txt

No nesting of the sequences is supported at the moment, but you can useseveral ones next to each other:

http://any.org/archive[1996-1999]/vol[1-4]/part{a,b,c}.html

You can specify any amount of URLs on the command line. They will be fetchedin a sequential manner in the specified order.

Since curl 7.15.1 you can also specify step counter for the ranges, so thatyou can get every Nth number or letter:

http://www.numericals.com/file[1-100:10].txt
http://www.letters.com/file[a-z:2].txt

If you specify URL without protocol:// prefix, curl will attempt to guess whatprotocol you might want. It will then default to HTTP but try other protocolsbased on often-used host name prefixes. For example, for host names startingwith "ftp." curl will assume you want to speak FTP.

Curl will attempt to re-use connections for multiple file transfers, so thatgetting many files from the same server will not do multiple connects /handshakes. This improves speed. Of course this is only done on filesspecified on a single command line and cannot be used between separate curlinvokes.

PROGRESS METER

curl normally displays a progress meter during operations, indicating amountof transferred data, transfer speeds and estimated time left etc.

However, since curl displays data to the terminal by default, if you invokecurl to do an operation and it is about to write data to the terminal, itdisables the progress meter as otherwise it would mess up the outputmixing progress meter and response data.

If you want a progress meter for HTTP POST or PUT requests, you need toredirect the response output to a file, using shell redirect (>), -o [file] orsimilar.

It is not the same case for FTP upload as that operation is not spitting outany response data to the terminal.

If you prefer a progress "bar" instead of the regular meter, -# is yourfriend.

OPTIONS

In general, all boolean options are enabled with --option and yet againdisabled with --no-option. That is, you use the exact same option namebut prefix it with "no-". However, in this list we mostly only list and showthe --option version of them. (This concept with --no options was added in7.19.0. Previously most options were toggled on/off on repeated use of thesame command line option.)

-a/--append

(FTP/SFTP) When used in an upload, this will tell curl to append to the targetfile instead of overwriting it. If the file doesn't exist, it will be created.Note that this flag is ignored by some SSH servers (including OpenSSH).

-A/--user-agent <agent string>

(HTTP) Specify the User-Agent string to send to the HTTP server. Some badlydone CGIs fail if this field isn't set to "Mozilla/4.0". To encode blanks inthe string, surround the string with single quote marks. This can also be setwith the -H/--header option of course.

If this option is set more than once, the last one will be the one that'sused.

--anyauth

(HTTP) Tells curl to figure out authentication method by itself, and use themost secure one the remote site claims it supports. This is done by firstdoing a request and checking the response-headers, thus possibly inducing anextra network round-trip. This is used instead of setting a specificauthentication method, which you can do with --basic, --digest,--ntlm, and --negotiate.

Note that using --anyauth is not recommended if you do uploads from stdin,since it may require data to be sent twice and then the client must be able torewind. If the need should arise when uploading from stdin, the uploadoperation will fail.

-b/--cookie <name=data>

(HTTP)Pass the data to the HTTP server as a cookie. It is supposedly thedata previously received from the server in a "Set-Cookie:" line.The data should be in the format "NAME1=VALUE1; NAME2=VALUE2".

If no '=' letter is used in the line, it is treated as a filename to use toread previously stored cookie lines from, which should be used in this sessionif they match. Using this method also activates the "cookie parser" which willmake curl record incoming cookies too, which may be handy if you're using thisin combination with the -L/--location option. The file format of thefile to read cookies from should be plain HTTP headers or the Netscape/Mozillacookie file format.

NOTE that the file specified with -b/--cookie is only used asinput. No cookies will be stored in the file. To store cookies, use the-c/--cookie-jar option or you could even save the HTTP headers to a fileusing -D/--dump-header!

If this option is set more than once, the last one will be the one that'sused.

-B/--use-ascii

Enable ASCII transfer when using FTP or LDAP. For FTP, this can also beenforced by using an URL that ends with ";type=A". This option causes datasent to stdout to be in text mode for win32 systems.

--basic

(HTTP) Tells curl to use HTTP Basic authentication. This is the default andthis option is usually pointless, unless you use it to override a previouslyset option that sets a different authentication method (such as --ntlm,--digest and --negotiate).

--ciphers <list of ciphers>

(SSL) Specifies which ciphers to use in the connection. The list of ciphersmust be using valid ciphers. Read up on SSL cipher list details on this URL:http://www.openssl.org/docs/apps/ciphers.html

NSS ciphers are done differently than OpenSSL and GnuTLS. The full list ofNSS ciphers is in the NSSCipherSuite entry at this URL:http://directory.fedora.redhat.com/docs/mod_nss.html#Directives

If this option is used several times, the last one will override the others.

--compressed

(HTTP) Request a compressed response using one of the algorithms libcurlsupports, and return the uncompressed document. If this option is used andthe server sends an unsupported encoding, curl will report an error.

--connect-timeout <seconds>

Maximum time in seconds that you allow the connection to the server to take.This only limits the connection phase, once curl has connected this option isof no more use. See also the -m/--max-time option.

If this option is used several times, the last one will be used.

-c/--cookie-jar <file name>

Specify to which file you want curl to write all cookies after a completedoperation. Curl writes all cookies previously read from a specified file aswell as all cookies received from remote server(s). If no cookies are known,no file will be written. The file will be written using the Netscape cookiefile format. If you set the file name to a single dash, "-", the cookies willbe written to stdout.

NOTEIf the cookie jar can't be created or written to, the whole curl operationwon't fail or even report an error clearly. Using -v will get a warningdisplayed, but that is the only visible feedback you get about this possiblylethal situation.

If this option is used several times, the last specified file name will beused.

-C/--continue-at <offset>

Continue/Resume a previous file transfer at the given offset. The given offsetis the exact number of bytes that will be skipped counted from the beginningof the source file before it is transferred to the destination. If used withuploads, the ftp server command SIZE will not be used by curl.

Use "-C -" to tell curl to automatically find out where/how to resume thetransfer. It then uses the given output/input files to figure that out.

If this option is used several times, the last one will be used.

--create-dirs

When used in conjunction with the -o option, curl will create the necessarylocal directory hierarchy as needed. This option creates the dirs mentionedwith the -o option, nothing else. If the -o file name uses no dir or if thedirs it mentions already exist, no dir will be created.

To create remote directories when using FTP or SFTP, try --ftp-create-dirs.

--crlf

(FTP) Convert LF to CRLF in upload. Useful for MVS (OS/390).

-d/--data <data>

(HTTP) Sends the specified data in a POST request to the HTTP server, in thesame way that a browser does when a user has filled in an HTML form andpresses the submit button. This will cause curl to pass the data to the serverusing the content-type application/x-www-form-urlencoded. Compare to-F/--form.

-d/--data is the same as --data-ascii. To post data purely binary,you should instead use the --data-binary option. To URL encode the valueof a form field you may use --data-urlencode.

If any of these options is used more than once on the same command line, thedata pieces specified will be merged together with a separating&-letter. Thus, using '-d name=daniel -d skill=lousy' would generate a postchunk that looks like 'name=daniel&skill=lousy'.

If you start the data with the letter @, the rest should be a file name toread the data from, or - if you want curl to read the data from stdin. Thecontents of the file must already be url-encoded. Multiple files can also bespecified. Posting data from a file named 'foobar' would thus be done with--data @foobar.

--data-binary <data>

(HTTP) This posts data exactly as specified with no extra processingwhatsoever.

If you start the data with the letter @, the rest should be a filename. Datais posted in a similar manner as --data-ascii does, except that newlinesare preserved and conversions are never done.

If this option is used several times, the ones following the first will appenddata. As described in -d/--data.

--data-urlencode <data>

(HTTP) This posts data, similar to the other --data options with the exceptionthat this performs URL encoding. (Added in 7.18.0)

To be CGI compliant, the <data> part should begin with a name followedby a separator and a content specification. The <data> part can be passed tocurl using one of the following syntaxes:

content: This will make curl URL encode the content and pass that on. Just be carefulso that the content doesn't contain any = or @ letters, as that will then makethe syntax match one of the other cases below!
=content: This will make curl URL encode the content and pass that on. The preceding =letter is not included in the data.
name=content: This will make curl URL encode the content part and pass that on. Note thatthe name part is expected to be URL encoded already.
@filename: This will make curl load data from the given file (including any newlines),URL encode that data and pass it on in the POST.
nameAATTfilename: This will make curl load data from the given file (including any newlines),URL encode that data and pass it on in the POST. The name part gets an equalsign appended, resulting in name=urlencoded-file-content. Note that thename is expected to be URL encoded already.

--digest

(HTTP) Enables HTTP Digest authentication. This is a authentication thatprevents the password from being sent over the wire in clear text. Use this incombination with the normal -u/--user option to set user name andpassword. See also --ntlm, --negotiate and --anyauth forrelated options.

If this option is used several times, the following occurrences make nodifference.

--disable-eprt

(FTP) Tell curl to disable the use of the EPRT and LPRT commands when doingactive FTP transfers. Curl will normally always first attempt to use EPRT,then LPRT before using PORT, but with this option, it will use PORT rightaway. EPRT and LPRT are extensions to the original FTP protocol, may not workon all servers but enable more functionality in a better way than thetraditional PORT command.

Since curl 7.19.0, --eprt can be used to explicitly enable EPRT againand --no-eprt is an alias for --disable-eprt.

--disable-epsv

(FTP) Tell curl to disable the use of the EPSV command when doing passive FTPtransfers. Curl will normally always first attempt to use EPSV before PASV,but with this option, it will not try using EPSV.

Since curl 7.19.0, --epsv can be used to explicitly enable EPRT againand --no-epsv is an alias for --disable-epsv.

-D/--dump-header <file>

Write the protocol headers to the specified file.

This option is handy to use when you want to store the headers that a HTTPsite sends to you. Cookies from the headers could then be read in a secondcurl invoke by using the -b/--cookie option! The -c/--cookie-jaroption is however a better way to store cookies.

When used on FTP, the ftp server response lines are considered being "headers"and thus are saved there.

If this option is used several times, the last one will be used.

-e/--referer <URL>

(HTTP) Sends the "Referer Page" information to the HTTP server. This can alsobe set with the -H/--header flag of course. When used with-L/--location you can append ";auto" to the --referer URL to make curlautomatically set the previous URL when it follows a Location: header. The";auto" string can be used alone, even if you don't set an initial --referer.

If this option is used several times, the last one will be used.

--engine <name>

Select the OpenSSL crypto engine to use for cipheroperations. Use --engine list to print a list of build-time supportedengines. Note that not all (or none) of the engines may be available atrun-time.

--environment

(RISC OS ONLY) Sets a range of environment variables, using the names the -woption supports, to easier allow extraction of useful information after havingrun curl.

--egd-file <file>

(SSL) Specify the path name to the Entropy Gathering Daemon socket. The socketis used to seed the random engine for SSL connections. See also the--random-file option.

-E/--cert <certificate[:password]>

(SSL) Tells curl to use the specified certificate file when getting a filewith HTTPS or FTPS. The certificate must be in PEM format. If the optionalpassword isn't specified, it will be queried for on the terminal. Note thatthis option assumes a "certificate" file that is the private key and theprivate certificate concatenated! See --cert and --key to specifythem independently.

If curl is built against the NSS SSL library then this option tellscurl the nickname of the certificate to use within the NSS database definedby the environment variable SSL_DIR (or by default /etc/pki/nssdb). If theNSS PEM PKCS#11 module (libnsspem.so) is available then PEM files may beloaded.

If this option is used several times, the last one will be used.

--cert-type <type>

(SSL) Tells curl what certificate type the provided certificate is in. PEM,DER and ENG are recognized types. If not specified, PEM is assumed.

If this option is used several times, the last one will be used.

--cacert <CA certificate>

(SSL) Tells curl to use the specified certificate file to verify the peer. Thefile may contain multiple CA certificates. The certificate(s) must be in PEMformat. Normally curl is built to use a default file for this, so this optionis typically used to alter that default file.

curl recognizes the environment variable named 'CURL_CA_BUNDLE' if that isset, and uses the given path as a path to a CA cert bundle. This optionoverrides that variable.

The windows version of curl will automatically look for a CA certs file named'curl-ca-bundle.crt', either in the same directory as curl.exe, or in theCurrent Working Directory, or in any folder along your PATH.

If curl is built against the NSS SSL library then this option tellscurl the nickname of the CA certificate to use within the NSS databasedefined by the environment variable SSL_DIR (or by default /etc/pki/nssdb).If the NSS PEM PKCS#11 module (libnsspem.so) is available then PEM filesmay be loaded.

If this option is used several times, the last one will be used.

--capath <CA certificate directory>

(SSL) Tells curl to use the specified certificate directory to verify thepeer. The certificates must be in PEM format, and the directory must have beenprocessed using the c_rehash utility supplied with openssl. Using--capath can allow curl to make SSL-connections much more efficientlythan using --cacert if the --cacert file contains many CAcertificates.

If this option is used several times, the last one will be used.

-f/--fail

(HTTP) Fail silently (no output at all) on server errors. This is mostly donelike this to better enable scripts etc to better deal with failed attempts. Innormal cases when a HTTP server fails to deliver a document, it returns anHTML document stating so (which often also describes why and more). This flagwill prevent curl from outputting that and return error 22.

This method is not fail-safe and there are occasions where non-successfulresponse codes will slip through, especially when authentication is involved(response codes 401 and 407).

--ftp-account [data]

(FTP) When an FTP server asks for "account data" after user name and passwordhas been provided, this data is sent off using the ACCT command. (Added in7.13.0)

If this option is used twice, the second will override the previous use.

--ftp-create-dirs

(FTP/SFTP) When an FTP or SFTP URL/operation uses a path that doesn'tcurrently exist on the server, the standard behavior of curl is tofail. Using this option, curl will instead attempt to create missingdirectories.

--ftp-method [method]

(FTP) Control what method curl should use to reach a file on a FTP(S)server. The method argument should be one of the following alternatives:

multicwd: curl does a single CWD operation for each path part in the given URL. For deephierarchies this means very many commands. This is how RFC1738 says it shouldbe done. This is the default but the slowest behavior.
nocwd: curl does no CWD at all. curl will do SIZE, RETR, STOR etc and give a fullpath to the server for all these commands. This is the fastest behavior.
singlecwd: curl does one CWD with the full target directory and then operates on the file"normally" (like in the multicwd case). This is somewhat more standardscompliant than 'nocwd' but without the full penalty of 'multicwd'.

--ftp-pasv

(FTP) Use PASV when transferring. PASV is the internal default behavior, butusing this option can be used to override a previous --ftp-port option. (Addedin 7.11.0)

If this option is used several times, the following occurrences make nodifference. Undoing an enforced PASV really isn't doable but you must theninstead enforce the correct EPRT again.

--ftp-alternative-to-user <command>

(FTP) If authenticating with the USER and PASS commands fails, send thiscommand. When connecting to Tumbleweed's Secure Transport server over FTPSusing a client certificate, using "SITE AUTH" will tell the server to retrievethe username from the certificate. (Added in 7.15.5)

--ftp-skip-pasv-ip

(FTP) Tell curl to not use the IP address the server suggests in its responseto curl's PASV command when curl connects the data connection. Instead curlwill re-use the same IP address it already uses for the controlconnection. (Added in 7.14.2)

This option has no effect if PORT, EPRT or EPSV is used instead of PASV.

--ftp-ssl

(FTP) Try to use SSL/TLS for the FTP connection. Reverts to a non-secureconnection if the server doesn't support SSL/TLS. See also--ftp-ssl-control and --ftp-ssl-reqd for different levels ofencryption required. (Added in 7.11.0)

--ftp-ssl-control

(FTP) Require SSL/TLS for the ftp login, clear for transfer. Allows secureauthentication, but non-encrypted data transfers for efficiency. Fails thetransfer if the server doesn't support SSL/TLS. (Added in 7.16.0)

--ftp-ssl-reqd

(FTP) Require SSL/TLS for the FTP connection.Terminates the connection if the server doesn't support SSL/TLS.(Added in 7.15.5)

--ftp-ssl-ccc

(FTP) Use CCC (Clear Command Channel)Shuts down the SSL/TLS layer after authenticating. The rest of thecontrol channel communication will be unencrypted. This allowsNAT routers to follow the FTP transaction. The default mode ispassive. See --ftp-ssl-ccc-mode for other modes.(Added in 7.16.1)

--ftp-ssl-ccc-mode [active/passive]

(FTP) Use CCC (Clear Command Channel)Sets the CCC mode. The passive mode will not initiate the shutdown, butinstead wait for the server to do it, and will not reply to theshutdown from the server. The active mode initiates the shutdown andwaits for a reply from the server.(Added in 7.16.2)

-F/--form <name=content>

(HTTP) This lets curl emulate a filled in form in which a user has pressed thesubmit button. This causes curl to POST data using the Content-Typemultipart/form-data according to RFC1867. This enables uploading of binaryfiles etc. To force the 'content' part to be a file, prefix the file namewith an @ sign. To just get the content part from a file, prefix the file namewith the letter <. The difference between @ and < is then that @ makes a fileget attached in the post as a file upload, while the < makes a text field andjust get the contents for that text field from a file.

Example, to send your password file to the server, where'password' is the name of the form-field to which /etc/passwd will be theinput:

curl -F password=@/etc/passwd www.mypasswords.com

To read the file's content from stdin instead of a file, use - where the filename should've been. This goes for both @ and < constructs.

You can also tell curl what Content-Type to use by using 'type=', in a mannersimilar to:

curl -F "web=@index.html;type=text/html" url.com

curl -F "name=daniel;type=text/foo" url.com

You can also explicitly change the name field of an file upload part bysetting filename=, like this:

curl -F "file=@localfile;filename=nameinpost" url.com

See further examples and details in the MANUAL.

This option can be used multiple times.

--form-string <name=string>

(HTTP) Similar to --form except that the value string for the namedparameter is used literally. Leading '@' and '<' characters, and the';type=' string in the value have no special meaning. Use this in preferenceto --form if there's any possibility that the string value mayaccidentally trigger the '@' or '<' features of --form.

-g/--globoff

This option switches off the "URL globbing parser". When you set this option,you can specify URLs that contain the letters {}[] without having them beinginterpreted by curl itself. Note that these letters are not normal legal URLcontents but they should be encoded according to the URI standard.

-G/--get

When used, this option will make all data specified with -d/--data or--data-binary to be used in a HTTP GET request instead of the POSTrequest that otherwise would be used. The data will be appended to the URLwith a '?' separator.

If used in combination with -I, the POST data will instead be appended to theURL with a HEAD request.

If this option is used several times, the following occurrences make nodifference. This is because undoing a GET doesn't make sense, but you shouldthen instead enforce the alternative method you prefer.

-h/--help

Usage help.

-H/--header <header>

(HTTP) Extra header to use when getting a web page. You may specify any numberof extra headers. Note that if you should add a custom header that has thesame name as one of the internal ones curl would use, your externally setheader will be used instead of the internal one. This allows you to make eventrickier stuff than curl would normally do. You should not replace internallyset headers without knowing perfectly well what you're doing. Remove aninternal header by giving a replacement without content on the right side ofthe colon, as in: -H "Host:".

curl will make sure that each header you add/replace get sent with the properend of line marker, you should thus not add that as a part of the headercontent: do not add newlines or carriage returns they will only mess things upfor you.

See also the -A/--user-agent and -e/--referer options.

This option can be used multiple times to add/replace/remove multiple headers.

--hostpubmd5 <md5>

Pass a string containing 32 hexadecimal digits. The string should be the 128bit MD5 checksum of the remote host's public key, curl will refuse theconnection with the host unless the md5sums match. This option is only for SCPand SFTP transfers. (Added in 7.17.1)

--ignore-content-length

(HTTP)Ignore the Content-Length header. This is particularly useful for serversrunning Apache 1.x, which will report incorrect Content-Length for fileslarger than 2 gigabytes.

-i/--include

(HTTP) Include the HTTP-header in the output. The HTTP-header includes thingslike server-name, date of the document, HTTP-version and more...

--interface <name>

Perform an operation using a specified interface. You can enter interfacename, IP address or host name. An example could look like:

curl --interface eth0:1 http://www.netscape.com/

If this option is used several times, the last one will be used.

-I/--head

(HTTP/FTP/FILE)Fetch the HTTP-header only! HTTP-servers feature the command HEADwhich this uses to get nothing but the header of a document. When usedon a FTP or FILE file, curl displays the file size and last modificationtime only.

-j/--junk-session-cookies

(HTTP) When curl is told to read cookies from a given file, this option willmake it discard all "session cookies". This will basically have the same effectas if a new session is started. Typical browsers always discard sessioncookies when they're closed down.

-k/--insecure

(SSL) This option explicitly allows curl to perform "insecure" SSL connectionsand transfers. All SSL connections are attempted to be made secure by usingthe CA certificate bundle installed by default. This makes all connectionsconsidered "insecure" to fail unless -k/--insecure is used.

See this online resource for further details:http://curl.haxx.se/docs/sslcerts.html

--keepalive-time <seconds>

This option sets the time a connection needs to remain idle before sendingkeepalive probes and the time between individual keepalive probes. It iscurrently effective on operating systems offering the TCP_KEEPIDLE andTCP_KEEPINTVL socket options (meaning Linux, recent AIX, HP-UX and more). Thisoption has no effect if --no-keepalive is used. (Added in 7.18.0)

If this option is used multiple times, the last occurrence sets the amount.

--key <key>

(SSL/SSH) Private key file name. Allows you to provide your private key in thisseparate file.

If this option is used several times, the last one will be used.

--key-type <type>

(SSL) Private key file type. Specify which type your --key providedprivate key is. DER, PEM and ENG are supported. If not specified, PEM isassumed.

If this option is used several times, the last one will be used.

--krb <level>

(FTP) Enable Kerberos authentication and use. The level must be entered andshould be one of 'clear', 'safe', 'confidential' or 'private'. Should you usea level that is not one of these, 'private' will instead be used.

This option requires that the library was built with kerberos4 or GSSAPI(GSS-Negotiate) support. This is not very common. Use -V/--version tosee if your curl supports it.

If this option is used several times, the last one will be used.

-K/--config <config file>

Specify which config file to read curl arguments from. The config file is atext file in which command line arguments can be written which then will beused as if they were written on the actual command line. Options and theirparameters must be specified on the same config file line, separated bywhite space, colon, the equals sign or any combination thereof (however,the preferred separator is the equals sign). If the parameter is to containwhite spaces, the parameter must be enclosed within quotes. Within doublequotes, the following escape sequences are available: \\, \", \t, \n,\r and \v. A backlash preceding any other letter is ignored. If thefirst column of a config line is a '#' character, the rest of the line will betreated as a comment. Only write one option per physical line in the configfile.

Specify the filename to -K/--config as '-' to make curl read the file fromstdin.

Note that to be able to specify a URL in the config file, you need to specifyit using the --url option, and not by simply writing the URL on its ownline. So, it could look similar to this:

url = "http://curl.haxx.se/docs/"

Long option names can optionally be given in the config file without theinitial double dashes.

When curl is invoked, it always (unless -q is used) checks for a defaultconfig file and uses it if found. The default config file is checked for inthe following places in this order:

1) curl tries to find the "home dir": It first checks for the CURL_HOME andthen the HOME environment variables. Failing that, it uses getpwuid() onunix-like systems (which returns the home dir given the current user in yoursystem). On Windows, it then checks for the APPDATA variable, or as a lastresort the '%USERPROFILE%Application Data'.

2) On windows, if there is no _curlrc file in the home dir, it checks for onein the same dir the executable curl is placed. On unix-like systems, it willsimply try to load .curlrc from the determined home dir.

# --- Example file ---# this is a commenturl = "curl.haxx.se"output = "curlhere.html"user-agent = "superagent/1.0"# and fetch another URL toourl = "curl.haxx.se/docs/manpage.html"-Oreferer = "http://nowhereatall.com/"# --- End of example file ---

This option can be used multiple times to load multiple config files.

--libcurl <file>

Append this option to any ordinary curl command line, and you will get alibcurl-using source code written to the file that does the equivalentoperation of what your command line operation does!

NOTE: this does not properly support -F and the sending of multipartformposts, so in those cases the output program will be missing necessarycalls to curl_formadd(3), and possibly more.

If this option is used several times, the last given file name will beused. (Added in 7.16.1)

--limit-rate <speed>

Specify the maximum transfer rate you want curl to use. This feature is usefulif you have a limited pipe and you'd like your transfer not use your entirebandwidth.

The given speed is measured in bytes/second, unless a suffix is appended.Appending 'k' or 'K' will count the number as kilobytes, 'm' or M' makes itmegabytes while 'g' or 'G' makes it gigabytes. Examples: 200K, 3m and 1G.

The given rate is the average speed, counted during the entire transfer. Itmeans that curl might use higher transfer speeds in short bursts, but overtime it uses no more than the given rate.

If you are also using the -Y/--speed-limit option, that option will takeprecedence and might cripple the rate-limiting slightly, to help keeping thespeed-limit logic working.

If this option is used several times, the last one will be used.

-l/--list-only

(FTP)When listing an FTP directory, this switch forces a name-only view.Especially useful if you want to machine-parse the contents of an FTPdirectory since the normal directory view doesn't use a standard lookor format.

This option causes an FTP NLST command to be sent. Some FTP serverslist only files in their response to NLST; they do not includesubdirectories and symbolic links.

--local-port <num>[-num]

Set a preferred number or range of local port numbers to use for theconnection(s). Note that port numbers by nature is a scarce resource thatwill be busy at times so setting this range to something too narrow mightcause unnecessary connection setup failures. (Added in 7.15.2)

-L/--location

(HTTP/HTTPS) If the server reports that the requested page has moved to adifferent location (indicated with a Location: header and a 3XX response code)this option will make curl redo the request on the new place. If used togetherwith -i/--include or -I/--head, headers from all requested pageswill be shown. When authentication is used, curl only sends its credentials tothe initial host. If a redirect takes curl to a different host, it won't beable to intercept the user+password. See also --location-trusted on howto change this. You can limit the amount of redirects to follow by using the--max-redirs option.

When curl follows a redirect and the request is not a plain GET (for examplePOST or PUT), it will do the following request with a GET if the HTTP responsewas 301, 302, or 303. If the response code was any other 3xx code, curl willre-send the following request using the same unmodified method.

--location-trusted

(HTTP/HTTPS) Like -L/--location, but will allow sending the name +password to all hosts that the site may redirect to. This may or may notintroduce a security breach if the site redirects you do a site to whichyou'll send your authentication info (which is plaintext in the case of HTTPBasic authentication).

--max-filesize <bytes>

Specify the maximum size (in bytes) of a file to download. If the filerequested is larger than this value, the transfer will not start and curl willreturn with exit code 63.

NOTE: The file size is not always known prior to download, and for such filesthis option has no effect even if the file transfer ends up being larger thanthis given limit. This concerns both FTP and HTTP transfers.

-m/--max-time <seconds>

Maximum time in seconds that you allow the whole operation to take. This isuseful for preventing your batch jobs from hanging for hours due to slownetworks or links going down. See also the --connect-timeout option.

If this option is used several times, the last one will be used.

-M/--manual

Manual. Display the huge help text.

-n/--netrc

Makes curl scan the .netrc (_netrc on Windows) file in the user'shome directory for login name and password. This is typically used for ftp onunix. If used with http, curl will enable user authentication. Seenetrc(4)orftp(1)for details on the file format. Curl will not complain if that filehasn't the right permissions (it should not be world nor groupreadable). The environment variable "HOME" is used to find the homedirectory.

A quick and very simple example of how to setup a .netrc to allow curlto ftp to the machine host.domain.com with user name 'myself' and password'secret' should look similar to:

machine host.domain.com login myself password secret

--netrc-optional

Very similar to --netrc, but this option makes the .netrc usageoptional and not mandatory as the --netrc does.

--negotiate

(HTTP) Enables GSS-Negotiate authentication. The GSS-Negotiate method wasdesigned by Microsoft and is used in their web applications. It is primarilymeant as a support for Kerberos5 authentication but may be also used alongwith another authentication methods. For more information see IETF draftdraft-brezak-spnego-http-04.txt.

If you want to enable Negotiate for your proxy authentication, then use--proxy-negotiate.

This option requires that the library was built with GSSAPI support. This isnot very common. Use -V/--version to see if your version supportsGSS-Negotiate.

When using this option, you must also provide a fake -u/--user option toactivate the authentication code properly. Sending a '-u :' is enough as theuser name and password from the -u option aren't actually used.

If this option is used several times, the following occurrences make nodifference.

-N/--no-buffer

Disables the buffering of the output stream. In normal work situations, curlwill use a standard buffered output stream that will have the effect that itwill output the data in chunks, not necessarily exactly when the data arrives.Using this option will disable that buffering.

Note that this is the negated option name documented. You can thus use--buffer to enforce the buffering.

--no-keepalive

Disables the use of keepalive messages on the TCP connection, as by defaultcurl enables them.

Note that this is the negated option name documented. You can thus use--keepalive to enforce keepalive.

--no-sessionid

(SSL) Disable curl's use of SSL session-ID caching. By default all transfersare done using the cache. Note that while nothing ever should get hurt byattempting to reuse SSL session-IDs, there seem to be broken SSLimplementations in the wild that may require you to disable this in order foryou to succeed. (Added in 7.16.0)

Note that this is the negated option name documented. You can thus use--sessionid to enforce session-ID caching.

--ntlm

(HTTP) Enables NTLM authentication. The NTLM authentication method wasdesigned by Microsoft and is used by IIS web servers. It is a proprietaryprotocol, reversed engineered by clever people and implemented in curl basedon their efforts. This kind of behavior should not be endorsed, you shouldencourage everyone who uses NTLM to switch to a public and documentedauthentication method instead. Such as Digest.

If you want to enable NTLM for your proxy authentication, then use--proxy-ntlm.

This option requires that the library was built with SSL support. Use-V/--version to see if your curl supports NTLM.

If this option is used several times, the following occurrences make nodifference.

-o/--output <file>

Write output to <file> instead of stdout. If you are using {} or [] to fetchmultiple documents, you can use '#' followed by a number in the <file>specifier. That variable will be replaced with the current string for the URLbeing fetched. Like in:

curl http://{one,two}.site.com -o "file_#1.txt"

or use several variables like:

curl http://{site,host}.host[1-5].com -o "#1_#2"

You may use this option as many times as you have number of URLs.

See also the --create-dirs option to create the local directoriesdynamically.

-O/--remote-name

Write output to a local file named like the remote file we get. (Only the filepart of the remote file is used, the path is cut off.)

The remote file name to use for saving is extracted from the given URL,nothing else.

You may use this option as many times as you have number of URLs.

--remote-name-all

This option changes the default action for all given URLs to be dealt with asif -O/--remote-name were used for each one. So if you want to disablethat for a specific URL after --remote-name-all has been used, you mustuse "-o -" or --no-remote-name. (Added in 7.19.0)

--pass <phrase>

(SSL/SSH) Pass phrase for the private key

If this option is used several times, the last one will be used.

--post301

Tells curl to respect RFC 2616/10.3.2 and not convert POST requests into GETrequests when following a 301 redirection. The non-RFC behaviour is ubiquitousin web browsers, so curl does the conversion by default to maintainconsistency. However, a server may requires a POST to remain a POST after sucha redirection. This option is meaningful only when using -L/--location(Added in 7.17.1)

--proxy-anyauth

Tells curl to pick a suitable authentication method when communicating withthe given proxy. This might cause an extra request/response round-trip. (Addedin 7.13.2)

--proxy-basic

Tells curl to use HTTP Basic authentication when communicating with the givenproxy. Use --basic for enabling HTTP Basic with a remote host. Basic isthe default authentication method curl uses with proxies.

--proxy-digest

Tells curl to use HTTP Digest authentication when communicating with the givenproxy. Use --digest for enabling HTTP Digest with a remote host.

--proxy-negotiate

Tells curl to use HTTP Negotiate authentication when communicatingwith the given proxy. Use --negotiate for enabling HTTP Negotiatewith a remote host. (Added in 7.17.1)

--proxy-ntlm

Tells curl to use HTTP NTLM authentication when communicating with the givenproxy. Use --ntlm for enabling NTLM with a remote host.

-p/--proxytunnel

When an HTTP proxy is used (-x/--proxy), this option will cause non-HTTPprotocols to attempt to tunnel through the proxy instead of merely using it todo HTTP-like operations. The tunnel approach is made with the HTTP proxyCONNECT request and requires that the proxy allows direct connect to theremote port number curl wants to tunnel through to.

--pubkey <key>

(SSH) Public key file name. Allows you to provide your public key in thisseparate file.

If this option is used several times, the last one will be used.

-P/--ftp-port <address>

(FTP) Reverses the initiator/listener roles when connecting with ftp. Thisswitch makes Curl use the PORT command instead of PASV. In practise, PORTtells the server to connect to the client's specified address and port, whilePASV asks the server for an ip address and port to connect to. <address>should be one of:

interface: i.e "eth0" to specify which interface's IP address you want to use (Unix only)
IP address: i.e "192.168.10.1" to specify exact IP number
host name: i.e "my.host.domain" to specify machine
-: make curl pick the same IP address that is already used for the controlconnection

If this option is used several times, the last one will be used. Disable theuse of PORT with --ftp-pasv. Disable the attempt to use the EPRT commandinstead of PORT by using --disable-eprt. EPRT is really PORT++.

-q

If used as the first parameter on the command line, the curlrc configfile will not be read and used. See the -K/--config for details on thedefault config file search path.

-Q/--quote <command>

(FTP/SFTP) Send an arbitrary command to the remote FTP or SFTP server. Quotecommands are sent BEFORE the transfer is taking place (just after theinitial PWD command in an FTP transfer, to be exact). To make commandstake place after a successful transfer, prefix them with a dash '-'.To make commands get sent after libcurl has changed working directory,just before the transfer command(s), prefix the command with '+' (thisis only supported for FTP). You may specify any number of commands. Ifthe server returns failure for one of the commands, the entire operationwill be aborted. You must send syntactically correct FTP commands asRFC959 defines to FTP servers, or one of the commands listed below toSFTP servers. This option can be used multiple times.

SFTP is a binary protocol. Unlike for FTP, libcurl interprets SFTP quotecommands before sending them to the server. Following is the list ofall supported SFTP quote commands:

chgrp group file: The chgrp command sets the group ID of the file named by the file operand to thegroup ID specified by the group operand. The group operand is a decimalinteger group ID.
chmod mode file: The chmod command modifies the file mode bits of the specified file. Themode operand is an octal integer mode number.
chown user file: The chown command sets the owner of the file named by the file operand to theuser ID specified by the user operand. The user operand is a decimalinteger user ID.
ln source_file target_file: The ln and symlink commands create a symbolic link at the target_file locationpointing to the source_file location.
mkdir directory_name: The mkdir command creates the directory named by the directory_name operand.
pwd: The pwd command returns the absolute pathname of the current working directory.
rename source target: The rename command renames the file or directory named by the sourceoperand to the destination path named by the target operand.
rm file: The rm command removes the file specified by the file operand.
rmdir directory: The rmdir command removes the directory entry specified by the directoryoperand, provided it is empty.
symlink source_file target_file: See ln.

--random-file <file>

(SSL) Specify the path name to file containing what will be considered asrandom data. The data is used to seed the random engine for SSL connections.See also the --egd-file option.

-r/--range <range>

(HTTP/FTP/FILE) Retrieve a byte range (i.e a partial document) from aHTTP/1.1, FTP server or a local FILE. Ranges can be specified in a number ofways.

0-499: specifies the first 500 bytes
500-999: specifies the second 500 bytes
-500: specifies the last 500 bytes
9500-: specifies the bytes from offset 9500 and forward
0-0,-1: specifies the first and last byte only(*)(H)
500-700,600-799: specifies 300 bytes from offset 500(H)
100-199,500-599: specifies two separate 100 bytes ranges(*)(H)

(*) = NOTE that this will cause the server to reply with a multipartresponse!

Only digit characters (0-9) are valid in 'start' and 'stop' of range syntax'start-stop'. If a non-digit character is given in the range, the server'sresponse will be indeterminable, depending on different server's configuration.

You should also be aware that many HTTP/1.1 servers do not have this featureenabled, so that when you attempt to get a range, you'll instead get the wholedocument.

FTP range downloads only support the simple syntax 'start-stop' (optionallywith one of the numbers omitted). It depends on the non-RFC command SIZE.

If this option is used several times, the last one will be used.

--raw

When used, it disables all internal HTTP decoding of content or transferencodings and instead makes them passed on unaltered, raw. (Added in 7.16.2)

-R/--remote-time

When used, this will make libcurl attempt to figure out the timestamp of theremote file, and if that is available make the local file get that sametimestamp.

--retry <num>

If a transient error is returned when curl tries to perform a transfer, itwill retry this number of times before giving up. Setting the number to 0makes curl do no retries (which is the default). Transient error means either:a timeout, an FTP 5xx response code or an HTTP 5xx response code.

When curl is about to retry a transfer, it will first wait one second and thenfor all forthcoming retries it will double the waiting time until it reaches10 minutes which then will be the delay between the rest of the retries. Byusing --retry-delay you disable this exponential backoff algorithm. Seealso --retry-max-time to limit the total time allowed forretries. (Added in 7.12.3)

If this option is used multiple times, the last occurrence decide the amount.

--retry-delay <seconds>

Make curl sleep this amount of time between each retry when a transfer hasfailed with a transient error (it changes the default backoff time algorithmbetween retries). This option is only interesting if --retry is alsoused. Setting this delay to zero will make curl use the default backoff time.(Added in 7.12.3)

If this option is used multiple times, the last occurrence decide the amount.

--retry-max-time <seconds>

The retry timer is reset before the first transfer attempt. Retries will bedone as usual (see --retry) as long as the timer hasn't reached thisgiven limit. Notice that if the timer hasn't reached the limit, the requestwill be made and while performing, it may take longer than this given timeperiod. To limit a single request's maximum time, use -m/--max-time.Set this option to zero to not timeout retries. (Added in 7.12.3)

If this option is used multiple times, the last occurrence decide the amount.

-s/--silent

Silent mode. Don't show progress meter or error messages. MakesCurl mute.

-S/--show-error

When used with -s it makes curl show error message if it fails.

--socks4 <host[:port]>

Use the specified SOCKS4 proxy. If the port number is not specified, it isassumed at port 1080. (Added in 7.15.2)

This option overrides any previous use of -x/--proxy, as they aremutually exclusive.

If this option is used several times, the last one will be used.

--socks4a <host[:port]>

Use the specified SOCKS4a proxy. If the port number is not specified, it isassumed at port 1080. (Added in 7.18.0)

This option overrides any previous use of -x/--proxy, as they aremutually exclusive.

If this option is used several times, the last one will be used.

--socks5-hostname <host[:port]>

Use the specified SOCKS5 proxy (and let the proxy resolve the host name). Ifthe port number is not specified, it is assumed at port 1080. (Added in7.18.0)

This option overrides any previous use of -x/--proxy, as they aremutually exclusive.

If this option is used several times, the last one will be used. (This optionwas previously wrongly documented and used as --socks without the numberappended.)

--socks5 <host[:port]>

Use the specified SOCKS5 proxy - but resolve the host name locally. If theport number is not specified, it is assumed at port 1080.

This option overrides any previous use of -x/--proxy, as they aremutually exclusive.

If this option is used several times, the last one will be used. (This optionwas previously wrongly documented and used as --socks without the numberappended.)

--stderr <file>

Redirect all writes to stderr to the specified file instead. If the file nameis a plain '-', it is instead written to stdout. This option has no point whenyou're using a shell with decent redirecting capabilities.

If this option is used several times, the last one will be used.

--tcp-nodelay

Turn on the TCP_NODELAY option. See the curl_easy_setopt(3) man page fordetails about this option. (Added in 7.11.2)

-t/--telnet-option <OPT=val>

Pass options to the telnet protocol. Supported options are:

TTYPE=<term> Sets the terminal type.

XDISPLOC=<X display> Sets the X display location.

NEW_ENV=<var,val> Sets an environment variable.

-T/--upload-file <file>

This transfers the specified local file to the remote URL. If there is no filepart in the specified URL, Curl will append the local file name. NOTE that youmust use a trailing / on the last directory to really prove to Curl that thereis no file name or curl will think that your last directory name is the remotefile name to use. That will most likely cause the upload operation to fail. Ifthis is used on a http(s) server, the PUT command will be used.

Use the file name "-" (a single dash) to use stdin instead of a given file.

You can specify one -T for each URL on the command line. Each -T + URL pairspecifies what to upload and to where. curl also supports "globbing" of the -Targument, meaning that you can upload multiple files to a single URL by usingthe same URL globbing style supported in the URL, like this:

curl -T "{file1,file2}" http://www.uploadtothissite.com

or even

curl -T "img[1-1000].png" ftp://ftp.picturemania.com/upload/

--trace <file>

Enables a full trace dump of all incoming and outgoing data, includingdescriptive information, to the given output file. Use "-" as filename to havethe output sent to stdout.

This option overrides previous uses of -v/--verbose or--trace-ascii.

If this option is used several times, the last one will be used.

--trace-ascii <file>

Enables a full trace dump of all incoming and outgoing data, includingdescriptive information, to the given output file. Use "-" as filename to havethe output sent to stdout.

This is very similar to --trace, but leaves out the hex part and onlyshows the ASCII part of the dump. It makes smaller output that might be easierto read for untrained humans.

This option overrides previous uses of -v/--verbose or --trace.

If this option is used several times, the last one will be used.

--trace-time

Prepends a time stamp to each trace or verbose line that curl displays.(Added in 7.14.0)

-u/--user <user:password>

Specify user and password to use for server authentication. Overrides-n/--netrc and --netrc-optional.

If you just give the user name (without entering a colon) curl will prompt fora password.

If you use an SSPI-enabled curl binary and do NTLM authentication, you canforce curl to pick up the user name and password from your environment bysimply specifying a single colon with this option: "-u :".

If this option is used several times, the last one will be used.

-U/--proxy-user <user:password>

Specify user and password to use for proxy authentication.

If this option is used several times, the last one will be used.

--url <URL>

Specify a URL to fetch. This option is mostly handy when you want to specifyURL(s) in a config file.

This option may be used any number of times. To control where this URL iswritten, use the -o/--output or the -O/--remote-name options.

-v/--verbose

Makes the fetching more verbose/talkative. Mostly usable for debugging. Linesstarting with '>' means "header data" sent by curl, '<' means "header data"received by curl that is hidden in normal cases and lines starting with '*'means additional info provided by curl.

Note that if you only want HTTP headers in the output, -i/--includemight be option you're looking for.

If you think this option still doesn't give you enough details, consider using--trace or --trace-ascii instead.

This option overrides previous uses of --trace-ascii or --trace.

-V/--version

Displays information about curl and the libcurl version it uses.

The first line includes the full version of curl, libcurl and other 3rd partylibraries linked with the executable.

The second line (starts with "Protocols:") shows all protocols that libcurlreports to support.

The third line (starts with "Features:") shows specific features libcurlreports to offer. Available features include:

IPv6: You can use IPv6 with this.
krb4: Krb4 for ftp is supported.
SSL: HTTPS and FTPS are supported.
libz: Automatic decompression of compressed files over HTTP is supported.
NTLM: NTLM authentication is supported.
GSS-Negotiate: Negotiate authentication and krb5 for ftp is supported.
Debug: This curl uses a libcurl built with Debug. This enables more error-trackingand memory debugging etc. For curl-developers only!
AsynchDNS: This curl uses asynchronous name resolves.
SPNEGO: SPNEGO Negotiate authentication is supported.
Largefile: This curl supports transfers of large files, files larger than 2GB.
IDN: This curl supports IDN - international domain names.
SSPI: SSPI is supported. If you use NTLM and set a blank user name, curl willauthenticate with your current user and password.

-w/--write-out <format>

Defines what to display on stdout after a completed and successfuloperation. The format is a string that may contain plain text mixed with anynumber of variables. The string can be specified as "string", to get read froma particular file you specify it "@filename" and to tell curl to read theformat from stdin you write "@-".

The variables present in the output format will be substituted by the value ortext that curl thinks fit, as described below. All variables are specifiedlike %{variable_name} and to output a normal % you just write them like%%. You can output a newline by using \n, a carriage return with \r and a tabspace with \t.

NOTE:The %-letter is a special letter in the win32-environment, where alloccurrences of % must be doubled when using this option.

Available variables are at this point:

url_effective: The URL that was fetched last. This is mostly meaningful if you've told curlto follow location: headers.
http_code: The numerical response code that was found in the last retrieved HTTP(S) orFTP(s) transfer. In 7.18.2 the alias response_code was added to show thesame info.
http_connect: The numerical code that was found in the last response (from a proxy) to acurl CONNECT request. (Added in 7.12.4)
time_total: The total time, in seconds, that the full operation lasted. The time will bedisplayed with millisecond resolution.
time_namelookup: The time, in seconds, it took from the start until the name resolving wascompleted.
time_connect: The time, in seconds, it took from the start until the TCP connect to theremote host (or proxy) was completed.
time_appconnect: The time, in seconds, it took from the start until the SSL/SSH/etcconnect/handshake to the remote host was completed. (Added in 7.19.0)
time_pretransfer: The time, in seconds, it took from the start until the file transfer is justabout to begin. This includes all pre-transfer commands and negotiations thatare specific to the particular protocol(s) involved.
time_redirect: The time, in seconds, it took for all redirection steps include name lookup,connect, pretransfer and transfer before final transaction wasstarted. time_redirect shows the complete execution time for multipleredirections. (Added in 7.12.3)
time_starttransfer: The time, in seconds, it took from the start until the first byte is just aboutto be transferred. This includes time_pretransfer and also the time theserver needs to calculate the result.
size_download: The total amount of bytes that were downloaded.
size_upload: The total amount of bytes that were uploaded.
size_header: The total amount of bytes of the downloaded headers.
size_request: The total amount of bytes that were sent in the HTTP request.
speed_download: The average download speed that curl measured for the complete download.
speed_upload: The average upload speed that curl measured for the complete upload.
content_type: The Content-Type of the requested document, if there was any.
num_connects: Number of new connects made in the recent transfer. (Added in 7.12.3)
num_redirects: Number of redirects that were followed in the request. (Added in 7.12.3)
redirect_url: When a HTTP request was made without -L to follow redirects, this variablewill show the actual URL a redirect would take you to. (Added in 7.18.2)
ftp_entry_path: The initial path libcurl ended up in when logging on to the remote FTPserver. (Added in 7.15.4)
ssl_verify_result: The result of the SSL peer certificate verification that was requested. 0means the verification was successful. (Added in 7.19.0)

If this option is used several times, the last one will be used.

-x/--proxy <proxyhost[:port]>

Use specified HTTP proxy. If the port number is not specified, it is assumedat port 1080.

This option overrides existing environment variables that sets proxy touse. If there's an environment variable setting a proxy, you can set proxy to"" to override it.

Note that all operations that are performed over a HTTP proxy willtransparently be converted to HTTP. It means that certain protocol specificoperations might not be available. This is not the case if you can tunnelthrough the proxy, as done with the -p/--proxytunnel option.

Starting with 7.14.1, the proxy host can be specified the exact same way asthe proxy environment variables, include protocol prefix (http://) andembedded user + password.

If this option is used several times, the last one will be used.

-X/--request <command>

(HTTP) Specifies a custom request method to use when communicating with theHTTP server. The specified request will be used instead of the methodotherwise used (which defaults to GET). Read the HTTP 1.1 specification fordetails and explanations.

(FTP)Specifies a custom FTP command to use instead of LIST when doing file listswith ftp.

If this option is used several times, the last one will be used.

-y/--speed-time <time>

If a download is slower than speed-limit bytes per second during a speed-timeperiod, the download gets aborted. If speed-time is used, the defaultspeed-limit will be 1 unless set with -y.

This option controls transfers and thus will not affect slow connects etc. Ifthis is a concern for you, try the --connect-timeout option.

If this option is used several times, the last one will be used.

-Y/--speed-limit <speed>

If a download is slower than this given speed, in bytes per second, forspeed-time seconds it gets aborted. speed-time is set with -Y and is 30 ifnot set.

If this option is used several times, the last one will be used.

-z/--time-cond <date expression>

(HTTP/FTP) Request a file that has been modified later than the given time anddate, or one that has been modified before that time. The date expression canbe all sorts of date strings or if it doesn't match any internal ones, ittries to get the time from a given file name instead! See thecurl_getdate(3) man pages for date expression details.

Start the date expression with a dash (-) to make it request for a documentthat is older than the given date/time, default is a document that is newerthan the specified date/time.

If this option is used several times, the last one will be used.

--max-redirs <num>

Set maximum number of redirection-followings allowed. If -L/--locationis used, this option can be used to prevent curl from following redirections"in absurdum". By default, the limit is set to 50 redirections. Set thisoption to -1 to make it limitless.

If this option is used several times, the last one will be used.

-0/--http1.0

(HTTP) Forces curl to issue its requests using HTTP 1.0 instead of using itsinternally preferred: HTTP 1.1.

-1/--tlsv1

(SSL)Forces curl to use TSL version 1 when negotiating with a remote TLS server.

-2/--sslv2

(SSL)Forces curl to use SSL version 2 when negotiating with a remote SSL server.

-3/--sslv3

(SSL)Forces curl to use SSL version 3 when negotiating with a remote SSL server.

-4/--ipv4

If libcurl is capable of resolving an address to multiple IP versions (whichit is if it is ipv6-capable), this option tells libcurl to resolve names toIPv4 addresses only.

-6/--ipv6

If libcurl is capable of resolving an address to multiple IP versions (whichit is if it is ipv6-capable), this option tells libcurl to resolve names toIPv6 addresses only.

-#/--progress-bar

Make curl display progress information as a progress bar instead of thedefault statistics.

FILES

~/.curlrc

: Default config file, see -K/--config for details.

ENVIRONMENT

http_proxy [protocol://]<host>[:port]: Sets proxy server to use for HTTP.
HTTPS_PROXY [protocol://]<host>[:port]: Sets proxy server to use for HTTPS.
FTP_PROXY [protocol://]<host>[:port]: Sets proxy server to use for FTP.
ALL_PROXY [protocol://]<host>[:port]: Sets proxy server to use if no protocol-specific proxy is set.
NO_PROXY <comma-separated list of hosts>: list of host names that shouldn't go through any proxy. If set to a asterisk'*' only, it matches all hosts.

EXIT CODES

There exists a bunch of different error codes and their corresponding errormessages that may appear during bad conditions. At the time of this writing,the exit codes are:

1: Unsupported protocol. This build of curl has no support for this protocol.
2: Failed to initialize.
3: URL malformat. The syntax was not correct.
5: Couldn't resolve proxy. The given proxy host could not be resolved.
6: Couldn't resolve host. The given remote host was not resolved.
7: Failed to connect to host.
8: FTP weird server reply. The server sent data curl couldn't parse.
9: FTP access denied. The server denied login or denied access to the particularresource or directory you wanted to reach. Most often you tried to change to adirectory that doesn't exist on the server.
11: FTP weird PASS reply. Curl couldn't parse the reply sent to the PASS request.
13: FTP weird PASV reply, Curl couldn't parse the reply sent to the PASV request.
14: FTP weird 227 format. Curl couldn't parse the 227-line the server sent.
15: FTP can't get host. Couldn't resolve the host IP we got in the 227-line.
17: FTP couldn't set binary. Couldn't change transfer method to binary.
18: Partial file. Only a part of the file was transferred.
19: FTP couldn't download/access the given file, the RETR (or similar) commandfailed.
21: FTP quote error. A quote command returned error from the server.
22: HTTP page not retrieved. The requested url was not found or returned anothererror with the HTTP error code being 400 or above. This return code onlyappears if -f/--fail is used.
23: Write error. Curl couldn't write data to a local filesystem or similar.
25: FTP couldn't STOR file. The server denied the STOR operation, used for FTPuploading.
26: Read error. Various reading problems.
27: Out of memory. A memory allocation request failed.
28: Operation timeout. The specified time-out period was reached according to theconditions.
30: FTP PORT failed. The PORT command failed. Not all FTP servers support the PORTcommand, try doing a transfer using PASV instead!
31: FTP couldn't use REST. The REST command failed. This command is used forresumed FTP transfers.
33: HTTP range error. The range "command" didn't work.
34: HTTP post error. Internal post-request generation error.
35: SSL connect error. The SSL handshaking failed.
36: FTP bad download resume. Couldn't continue an earlier aborted download.
37: FILE couldn't read file. Failed to open the file. Permissions?
38: LDAP cannot bind. LDAP bind operation failed.
39: LDAP search failed.
41: Function not found. A required LDAP function was not found.
42: Aborted by callback. An application told curl to abort the operation.
43: Internal error. A function was called with a bad parameter.
45: Interface error. A specified outgoing interface could not be used.
47: Too many redirects. When following redirects, curl hit the maximum amount.
48: Unknown TELNET option specified.
49: Malformed telnet option.
51: The peer's SSL certificate or SSH MD5 fingerprint was not ok
52: The server didn't reply anything, which here is considered an error.
53: SSL crypto engine not found
54: Cannot set SSL crypto engine as default
55: Failed sending network data
56: Failure in receiving network data
58: Problem with the local certificate
59: Couldn't use specified SSL cipher
60: Peer certificate cannot be authenticated with known CA certificates
61: Unrecognized transfer encoding
62: Invalid LDAP URL
63: Maximum file size exceeded
64: Requested FTP SSL level failed
65: Sending the data requires a rewind that failed
66: Failed to initialise SSL Engine
67: User, password or similar was not accepted and curl failed to login
68: File not found on TFTP server
69: Permission problem on TFTP server
70: Out of disk space on TFTP server
71: Illegal TFTP operation
72: Unknown TFTP transfer ID
73: File already exists (TFTP)
74: No such user (TFTP)
75: Character conversion failed
76: Character conversion functions required
77: Problem with reading the SSL CA cert (path? access rights?)
78: The resource referenced in the URL does not exist
79: An unspecified error occurred during the SSH session
80: Failed to shut down the SSL connection
82: Could not load CRL file, missing or wrong format (added in 7.19.0)
83: Issuer check failed (added in 7.19.0)
XX: There will appear more error codes here in future releases. The existing onesare meant to never change.